[3.19.y-ckt stable] Patch "KVM: MMU: fix CR4.SMEP=1, CR0.WP=0 with shadow pages" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    KVM: MMU: fix CR4.SMEP=1, CR0.WP=0 with shadow pages

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From b511ecd63ff96cbe0c5d759e81c6a81f4c940106 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini at redhat.com>
Date: Thu, 2 Apr 2015 11:04:05 +0200
Subject: KVM: MMU: fix CR4.SMEP=1, CR0.WP=0 with shadow pages

commit 898761158be7682082955e3efa4ad24725305fc7 upstream.

smep_andnot_wp is initialized in kvm_init_shadow_mmu and shadow pages
should not be reused for different values of it.  Thus, it has to be
added to the mask in kvm_mmu_pte_write.

Reviewed-by: Xiao Guangrong <guangrong.xiao at linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/x86/kvm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index f83fc6c..2dfca9b 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4125,7 +4125,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 	++vcpu->kvm->stat.mmu_pte_write;
 	kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE);

-	mask.cr0_wp = mask.cr4_pae = mask.nxe = 1;
+	mask.cr0_wp = mask.cr4_pae = mask.nxe = mask.smep_andnot_wp = 1;
 	for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
 		if (detect_write_misaligned(sp, gpa, bytes) ||
 		      detect_write_flooding(sp)) {
--
1.9.1